On Sun, Jul 21, 2013 at 01:16:24PM +0200, Daniel Vetter wrote: > The regression fix for gen6+ rps fallout > > commit 7dcd2677ea912573d9ed4bcd629b0023b2d11505 > Author: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> > Date: Wed Jul 17 10:22:58 2013 +0400 > > drm/i915: fix long-standing SNB regression in power consumption after resume > > unintentionally also changed the init sequence ordering between > gt_init and gt_reset - we need to reset BIOS damage like leftover > forcewake references before we run our own code. Otherwise we can get > nasty dmesg noise like > > [drm:__gen6_gt_force_wake_mt_get] *ERROR* Timed out waiting for forcewake old ack to clear. > > again. Since _reset suggests that we first need to have stuff > initialized (which isn't the case here) call it sanitze instead. > > While at it also block out the rps disable introduce by the above > commit on ilk: We don't have any knowledge of ilk rps being broken in > similar ways. And the disable functions uses the default hw state > which is only read out when we're enabling rps. So essentially we've > been writing random grabage into that register. > > Reported-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> > Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Indeed, on ilk this does look a bit fishy. Tested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> -Chris -- Chris Wilson, Intel Open Source Technology Centre -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html